In many transportation operations, payment is determined by the weight of the load carried by the vehicle, e.g., truck. For example, in the buying and selling of bulk grain, the sales or purchase price is usually determined by calculating the net weight of the grain carried by the vehicle. Similarly, household moving companies usually calculate their moving charges based upon the net weight of the load carried by the moving van.
In these transportation operations, the net weight of the load may be determined by weighing the vehicle twice. First, the vehicle may be weighed in the unloaded or empty state to obtain unloaded or tare weight. Second, after loading, the vehicle may be weighed again to obtain the loaded or gross weight of the vehicle. The net weight of the load may then be readily calculated by subtracting the tare weight from the gross weight of the vehicle. The particular order in which the vehicle is weighed to obtain the tare weight and gross weight is also usually not critical. For example, the vehicle may be weighed to measure and obtain the loaded or gross weight of the vehicle first, followed by measuring and obtaining the unloaded or tare weight of the vehicle, before calculating, for example, the net weight of the loaded vehicle.
During the weighing operation, the operator of the vehicle being weighed may inadvertently or even purposefully position the vehicle improperly within the weighing area (e.g., weighing platform) of the weigh scale such as a platform scale, pit scale, etc. For example, one or more of the wheels, usually either on the front most axle or rear most axle of the vehicle, may be located off of or outside of the weighing area of the scale, meaning that the vehicle is not correctly positioned for an actual or true weighing of the vehicle. With the vehicle being incorrectly positioned, the weight registered by the scale normally would be lighter than the actual or true weight of the vehicle, be it loaded or unloaded, causing a reading known as “lightweighting.” If such incorrect positioning and weighing occurs when the unloaded or tare weight of the vehicle is being determined, such “lightweighting” will result in a net weight of the load which is determined to be inaccurately high, and thus the operator of the vehicle, if paid on a net weight of load basis, will be paid more than the load is actually worth.